Verilog Help

I would consider myself a novice in verilog. So here is the code that my teacher gave us for an unsigned multiplier, but I can't seem to get an output from it. Can anyone help? I wrote a testbench to test different inputs and get nothing for the output. I am trying to instantiate this in a 5x5 signed multiplier for the project, but his code isn't working. Here's the code: